Cytogenetic clonality in myelodysplastic syndromes studied with fluorescence in situ hybridization: lineage, response to growth factor therapy, and clone expansion

Abstract

Clonality in myelodysplastic syndromes (MDS) has been studied with various techniques including glucose-6-phosphate dehydrogenase (G6PD) isoenzyme and cytogenetic analyses, and with molecular techniques such as gene deletion studies and the analysis of restriction fragment- length polymorphisms (RFLP) of X-linked genes. In this study, we investigated the use of fluorescence in situ hybridization (FISH) with a chromosome-specific probe to examine cytogenetic clonality in peripheral blood (PB) cells from three patients with MDS. In each case, trisomy 8 was shown by conventional cytogenetic analysis at the time of the initial diagnosis. By using FISH with a probe for the centromere of chromosome 8, we identified the trisomy in individual PB cells from Wright-stained smears. With this technique, we could determine the cell lineage involved by the trisomy, and through serial analyses we could assess the response of the clonal and nonclonal cells to growth-factor therapy, and the expansion of the trisomic clone over time. In each of the three cases, various proportions of granulocytes, monocytes, eosinophils, and basophils showed trisomy 8 by FISH analysis. In none of the cases did we detect trisomy 8 in lymphocytes. By analysis of PB cells before and during therapy with recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF), we found that GM-CSF stimulated both trisomic and disomic cells. During a 1-year period of sequential study, we detected an abrupt increase in the percentage of trisomic cells in one patient, a stable percentage in another, and a slowly increasing percentage in the third. The abrupt increase in the first patient preceded a transformation to a more acute phase by 2 months. We conclude that FISH analysis of PB cells of patients with MDS offers an additional approach to the study of clonality in this disorder. In some cases this analysis may provide a useful and simple means of assessing response to therapy and progression of disease.

The Genomics of Myelodysplastic Syndromes: Origins of Disease Evolution, Biological Pathways, and Prognostic Implications

“…Additionally, single-nucleotide polymorphism microarrays and array comparative genomic hybridization are utilized to detect chromosomal abnormalities [ 21 , 22 ], while fluorescence in situ hybridization (FISH) is used to detect microdeletion [ 23 ]. Given the heterogeneity of MDS, the diagnosis of MDS is assessed by various morphologic tests on bone marrow smears and core biopsy (iron and Wright staining) and flow cytometric analysis to define the cellular immunophenotype.…”

Current View of miRNA with Tumor Suppressor Function, Exploring MDS and AML as Models

“…The cytopenias found in this disease arise from early apoptosis in the myeloid maturation process, 8,9 but unlike in leukemia, cells retain their capacity to mature fully. 10 There are many subtypes of this disease, stratified by pathologic findings in peripheral blood samples and bone marrow biopsies, karyo-type abnormalities, and defining mutations. The combination of these factors determines the patient's prognosis, risk for transformation to AML, and response to treatment.…”

Pathogenetic Aspects of Myelodysplastic Syndromes

“…More recently clonality studies have attempted to assess whether normal residual haemopoietic tissue survives in the dysplatic marrow. The persistence of normal progenitor cells in MDS has been suggested by the reappearance of polyclonal haemopoiesis in sorne cases, but not all, treated with G-CSF or GM-CSF [113,114], or chemotherapy [115]. Asano et al [116] demonstrated that nonclonal haemopoietic progenitor cell populations produce erythroid and non-erythroid colonies, grown in the presence of erythropoietin and GM-CSF, in 3/5 patients with MDS.…”